Farm specialisation and the general abandonment of mixed farming is a significant factor in the declines of biodiversity, including genetic resources for food and agriculture and wildlife, and of the disintegration of traditional and community-based management. The adoption of high-yielding, uniform cultivars has led to a considerable reduction in the number of genetically viable species used in agriculture. Many food crop varieties have virtually disappeared from their centres of diversity.
There is now an increasing body of evidence that organic agriculture supports much higher level of biodiversity than conventional farming systems, including species that have significantly declined. This paper addresses the contribution of organic agriculture to agricultural biodiversity, including genetic resources for food and agriculture. The positive impact of organic agriculture on wildlife (e.g. soil organisms, arable flora, predatory invertebrates, pollinators, birds) and in creating and connecting habitats that enhance nature conservation is outside the scope of this paper. The adverse impact of genetically modified organisms on organic agriculture is also outside the scope of this paper.
The cases presented in this document illustrate how organic agriculture, to be viable, is reversing the decline in species diversity as well as abundance of each species. If biodiversity is to be maintained, it should be an integral part of a healthy landscape where not only diversity but also abundance is a fundamental factor.
The close relationship between organic agriculture and agricultural biodiversity is expressed at the philosophical and theoretical levels in the basic principles, standards and regulations that govern organic agriculture and by the practical experiences of organic farmers around the world.
According to the FAO/WHO Codex Alimentarius Guidelines for Organic Food "Organic agriculture is a holistic production management system which promotes and enhances ecosystem health, including biological cycles and soil biological activity ... The primary goal of organic agriculture is to optimise the health and productivity of inter-dependent communities of soil life, plants, animals and people".
The adoption of organic agriculture methods requires farmers to follow a series of agronomic practices (e.g. essentially rotations and associations of a large number of plants and animals) that make organically managed systems biologically much more complex than conventionally managed systems. The organic agriculture system relies on the creation and maintenance of conditions that positively nurture the health of crops and livestock and on harnessing of natural processes (instead of using artificial inputs). Many involve the positive use of biodiversity, thus making the conservation of biodiversity an integral part of the farming activity.
There are millions of small farmers in developing countries who do not have the economic means to buy high yielding seeds or the fertilizers and pesticides necessary for their cultivation. Many of these have opted for the maintenance or re-introduction of organic systems based on traditional forms of agriculture. These promote the use of varieties that are better adapted to local biotic and abiotic conditions (e.g. biological control of pests and diseases, climatic stress).
Convincing farmers to adopt organic agricultural techniques is not a difficult task. Many farmers, besides cultivating high yielding varieties that require large amounts of off-farm inputs, have continued to plant a part of their land with crops for self-consumption, using natural methods.
In developed countries, the role of organic agriculture in the restoration and maintenance of species, varieties and breeds at the risk of extinction have also led many organizations or individuals to adopt this system to save genetic, specie and ecosystem diversity. Conservation efforts, through organic management, are however even more important in centres of diversity. In these areas, cultivation of populations with high genetic variability is an indispensable inheritance for agriculture and as such, for food security for future generations.
The price premiums which organic products command (and in Northern countries, payments received for organic agriculture) give an economic value to biodiversity and to the efficient use of resources. There are farmers who farm organically because they are attracted by the strong demand for organic products. For these farmers, conversion to organic management is a way of adding value to production and for obtaining better prices on the market. These farmers are required to implement a minimum level of biodiversity in order to be granted the organic label. In fact, crop rotation is the first step towards improving agricultural biodiversity. This is one of the methods required by organic certification bodies, as well as by financial support programmes. For the organic system to be economically viable, market-driven farmers are led to use local species, varieties and breeds that are more resistant to disease and local environmental conditions in order to compensate for the restriction on synthetic input use.
By choice or by necessity, organic farmers do not make use of synthetic agricultural inputs. They rather rely on the "natural inputs" by enhancing biodiversity through in situ conservation and sustainable use of genetic resources. Independent of the motives that farmers have for the adoption of organic agriculture, in every case a marked increase in biodiversity is visible. Many of these empirical systems have given satisfactory results and have since become the focus of study in research centres.
When diversity is encouraged, locally adapted plant and animal breeds which are more appropriate to local ecosystems can be used. Most importantly, agricultural genetic diversity is a basic insurance against crop and livestock disease outbreaks.
Organic farmers breed varieties for quality, nutrition, resistance and yield, in reduced input growing conditions. Research has shown that these characteristics are more likely to be found in older native cultivars. In particular, open pollinated varieties offer diverse and regionally adapted characteristics that are better suited to organic agriculture. Open pollinated varieties, which represent an important gene pool for resource-poor farmers living in marginalized and stress-prone areas, are rapidly vanishing. They are replaced by very few hybrid varieties which require inputs not available to poor farmers and which entail dependence on large seed companies. A significant proportion of local breeds remains in the care of pastoral people and traditional livestock owners in developing countries (e.g. pigs in China, cows in India and poultry in Asia and Latin America). Local breeds are robust and suitable for free ranging; however, two local breeds are becoming extinct every week.
Organic systems encourage the preservation and expansion of older, locally bred and indigenous varieties and breeds. Farmers who save their own seeds can gradually increase crop resistance to pests and diseases by breeding for "horizontal resistance". Horizontal resistance is the ability of a crop to resist many or all strains of a particular pest (which differs from breeding for "vertical resistance" to have a gene to resist one specific strain of a disease). By exposing population of plants to a certain disease or pest (or to several pests at one time), then selecting a group of the most resistant plants and interbreeding them for several generations, a given population becomes more resistant than the original population. Horizontally resistant cultivars are well adapted to the environment in which they were bred, but may be less suitable for other growing conditions.
Many indigenous groups have an expert knowledge of biodiversity in their own areas. Traditionally, these groups have conserved, improved and shared genetic resources according to their food preferences and socio-economic and environmental conditions.
Following are a series of 16 case studies, selected from published materials from diverse sources including intergovernmental, governmental and private organizations. In all of these, the close relationship between the introduction of the organic agricultural system and the maintenance of biodiversity is evident, as is the resulting improvement in the socio-economic conditions of the farmers.
The case studies are presented according to the main contribution they make to the different aspects of agricultural biodiversity, including: